The present invention relates to means for electromagnetic shielding and electromagnetic noise suppression in the electric and electronic industries and, in particular, to a tape to be used therefor.
Conventionally, in the electric and electronic industries, tapes using Cu, Al or stainless sheets have been known for magnetic shielding or electric connection. Such a tape has a width of about 10 to 20 mm and a thickness of about 0.1 to 0.3 mm, and is wound in a belt fashion. Adhesive tapes obtained by applying an adhesive to the foregoing Cu, Al or stainless tapes have also been known. Further, as self-welding tapes, those obtained by applying a self-welding agent, such as polyester or polyamide, to the foregoing Cu, Al or stainless tapes have been known.
There is a possibility that electronic equipments may malfunction due to undesired electromagnetic waves (electromagnetic noise) from the exterior. As such electromagnetic noise, there are electromagnetic waves caused by other communications, undesired electromagnetic waves radiated from various kinds of equipments and devices used therein, and electromagnetic waves due to reflection. Therefore, shielding is essential in electronic equipments and various kinds of equipments radiating undesired electromagnetic waves for preventing radiation of the electromagnetic waves and invasion of the electromagnetic waves from the exterior.
In view of this, conductor plates (shield plates) have been used in these equipments. If the shield plates are used, the number of parts of the equipment is increased to cause high cost.
Accordingly, for realizing a shield effect easily and cheaply, it is considered to use the foregoing tapes.
However, the foregoing conventional tape is small in magnetic shield effect relative to high frequency waves of portable telephones, PHS""s, transceivers, electronic equipments or the like, particularly, electromagnetic waves at several hundred to thousand MHz bands. Therefore, there has been necessity for such tapes as having the magnetic shield effect over the wide frequency band, instead of the conventional tapes.
Further, if the foregoing tape or shield plate is used carelessly, there is raised a problem that the tape or shield plate may function as an antenna or secondary radiant noise due to reflection may be generated, so as to cause an influence to other devices in the same equipment.
An object of the present invention is to provide an electromagnetic interference suppressing tape which can protect an equipment from undesired electromagnetic waves from the exterior and prevent even radiant noise and/or reflection noise in the same equipment, and further can be easily used.
The present invention, as recited in claim 1, provides a composite magnetic tape characterized by comprising a thin film of a composite magnetic body formed by dispersing soft magnetic powder into an organic binding agent.
Further, the present invention, as recited in claim 2, provides a composite magnetic tape characterized by comprising a thin film of a multilayered structure in which a composite magnetic layer formed by dispersing soft magnetic powder into an organic binding agent and a conductor layer are stacked.
Modifications by the present invention and typical examples of carrying-out manners are recited in dependent claims.